Donepezil is an acetylcholinesterase inhibitor with the chemical structure 2,3-Dihydro-5,6-dimethoxy-2-[[1-(phenylmethyl)-4-piperidinyl]methyl]-1H-inden-1-one:
Donepezil has a molecular weight of 379.5 and is lipophilic (Log P value 3.08-4.11).
An oral tablet of donepezil hydrochloride (ARICEPT®) is approved in the U.S. for use in treating Alzheimer's dementia. Due to the nature of cognitive disorders, oral medications may be subject to problems with patient compliance especially for formulations that need to be taken throughout the day. Delivery of medications by transdermal, injection, or rectal routes to patients suffering from cognitive disorders has been investigated. U.S. Pat. No. 7,858,114 describes a percutaneous absorption preparation of donepezil for use as a plaster for long term delivery of an anti-dementia drug. U.S. Patent No. 2014/0370076 describes a transdermal drug delivery system comprising donepezil or a salt thereof that uses an acrylate-rubber hybrid adhesive that is prepared by a process without n-hexane. U.S. Pat. No. 4,895,841 to Eisai Co., Ltd. describes cyclic amine compounds including donepezil for use in treating dementia including Alzheimer senile dementia, Huntington's chorea, Pick's disease, and ataxia. Other transdermal delivery systems proposed use an overlay or other rate-limiting membrane to control delivery of the drug from the transdermal device, see e.g. U.S. Published Application No. 2010/0178307 which describes the use of a first and second overlay. Despite these teachings, there are no donepezil transdermal patches or devices available in the United States.
Delivery of anti-dementia drugs over a long period of time (e.g. several days or more) is difficult. Transdermal delivery of basic drugs including donepezil can be especially difficult due to poor skin permeability. Further, some active agents have poor or low solubility in the adhesives and/or other components used in typical transdermal formulations. Further, there is a need for stable, long term administration of anti-dementia agents (e.g. 1-10 days or more) that provides a stable and effective release of the agent over the administration period and has suitable adhesion for the long term administration.
Therefore, there exists a need for transdermal compositions, devices and methods that address these shortcomings.
The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.